Welcome to YT!
I don't think you have anything to worry about. Sounds to me like normal pack order establishing. As long as they aren't hurting each other, I'd let them do their thing, and only intervene if it looks problematic. Also, young puppies DO nip and bite, and you can teach them that it is not appropriate.
When Chloe was brand new, we had a heck of a time getting her to stop the normal playful nipping and biting. We use this technique where we would gently wrap our hand around her snout when she bites (not hard, but in a soft hold that shows you're in control) and gentle wiggle and say in a low deep voice No bite! Eventually, she'd start rolling over on her back, and she'd lick. At that point, we'd say "good girl" and let her be on her merry way. This worked the best for us.
Even now, once in a while when playing, she'll get a little mouthy, and all I have to say is the low and deep NO bite! and she's on her back.
good luck!
